Table 1 Demographic characteristics of the 2612 adolescent students

Mean age (SD)

12.78 (1.29)

Age range

11–16 years

Gender n (%)

 Girls

1397 (53.5%)

 Boys

1215 (46.5%)

Ethnicity n (%)

 Caucasian

358 (13.7%)

 African American

1582 (60.6%)

 Hispanic American

672 (25.7%)

Socio economic status n (%)

 No lunch discount

742 (28.4%)

 Reduced lunch fee

200 (7.7%)

 Free lunch

1670 (63.9%)